eibbed, interesting observations. i started a thread in the general stuff section about that very subject...
http://www.dr1.com/forums/general-stuff/97066-dominicans-u-s-can-you-identify.html
but by the same account, most latinamericans are of mixed race..most had blacks and mulattos and mestizos involved in founding the country..even if they dont look black anymore....
africans are crucial to all of latinamerican culture. without them, it wouldnt be what it is. so much of latinamerica is influenced by those roots...even where they dont look it. they are as crucial as the indigenous and spaniard influences. latinamerica isnt "of spaniards" it is the MIX that came about from their colonization: the blending of customs and cultures that made us who we are now.
so any latinamerican who does that would be excluding their indigenous and/or possible african descendence down the line, by your theory. i think the only reason it seems more questionable for people who appear to be black to claim "latino" is because they appear black. plain and simple.
you dont exclude people for being an indio. or an indio/spaniard mix. but an african/indio/spaniard mix? uh oh.
if we get into details, really, who other than SPANIARDS can claim to be latino? it seems no one else would fit the bill because they are most likely mixed. these darn boxes.